Datasheet

ManualsBrandsANALOG DEVICES ManualsLinear ICsADM2487EBRWZ-REEL7

2.5 kV Isolated RS-485 Transceivers with

Integrated Transformer Driver

ADM2482E/ADM2487E

Rev. A

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FEATURES

Isolated RS-485/RS-422 transceivers, configurable as half

duplex or full duplex

Integrated oscillator driver for external transformer

±15 kV ESD protection on RS-485 input/output pins

Complies with TIA/EIA-485-A-98 and ISO 8482:1987(E)

Data rate: 500 kbps/16 Mbps

5 V or 3.3 V operation (V

DD1

)

256 nodes on bus

True fail-safe receiver inputs

Safety and regulatory approvals

UL recognition: 2500 V rms for 1 minute per UL 1577

VDE certificates of conformity

DIN VVDE V 0884-10 (VDE V 0884-10):2006-12

IORM

= 560 V peak

Thermal shutdown protection

Operating temperature range: −40°C to +85°C

Wide-body, 16-lead SOIC package

APPLICATIONS

Isolated RS-485/RS-422 interfaces

Industrial field networks

Multipoint data transmission systems

FUNCTIONAL BLOCK DIAGRAM

DD1

DD2

D1 D2

TxD

RxD

GND

OSC

GALVANIC ISOLATION

07379-001

Figure 1.

GENERAL DESCRIPTION

The ADM2482E/ADM2487E are isolated data transceivers with

±15 kV ESD protection and are suitable for high speed, half-

duplex or full-duplex communication on multipoint transmission

lines. For half-duplex operation, the transmitter outputs and

receiver inputs share the same transmission line. Transmitter

Output Pin Y is linked externally to Receiver Input Pin A, and

Transmitter Output Pin Z to Receiver Input Pin B. The parts are

designed for balanced transmission lines and comply with

TIA/EIA-485-A-98 and ISO 8482:1987(E).

The devices employ the Analog Devices, Inc., iCoupler®

technology to combine a 3-channel isolator, a three-state

differential line driver, and a differential input receiver into a

single package. An on-chip oscillator outputs a pair of square

waveforms that drive an external transformer to provide isolated

power. The logic side of the device is powered with either a 5 V

or a 3.3 V supply, and the bus side is powered with an isolated

3.3 V supply.

The ADM2482E/ADM2487E driver has an active high enable,

and the receiver has an active low enable. The driver output

enters a high impedance state when the driver enable signal

is low. The receiver output enters a high impedance state when

the receiver enable signal is high.

The device has current-limiting and thermal shutdown features

to protect against output short circuits and situations where bus

contention might cause excessive power dissipation. The part is

fully specified over the industrial temperature range of −40°C to

+85°C and is available in a 16-lead, wide-body SOIC package.

Summary of content (20 pages)

PAGE 1
2.5 kV Isolated RS-485 Transceivers with Integrated Transformer Driver ADM2482E/ADM2487E FEATURES FUNCTIONAL BLOCK DIAGRAM VDD1 VDD2 D1 D2 OSC DE GALVANIC ISOLATION TxD RxD Y Z A B RE GND1 GND2 07379-001 Isolated RS-485/RS-422 transceivers, configurable as half duplex or full duplex Integrated oscillator driver for external transformer ±15 kV ESD protection on RS-485 input/output pins Complies with TIA/EIA-485-A-98 and ISO 8482:1987(E) Data rate: 500 kbps/16 Mbps 5 V or 3.
PAGE 2
ADM2482E/ADM2487E TABLE OF CONTENTS Features .............................................................................................. 1 Test Circuits ..................................................................................... 12 Applications ....................................................................................... 1 Switching Characteristics .............................................................. 13 Functional Block Diagram ...........................................
PAGE 3
ADM2482E/ADM2487E SPECIFICATIONS Each voltage is relative to its respective ground; 3.0 V ≤ VDD1 ≤ 5.5 V, 3.0 V ≤ VDD2 ≤ 3.6 V. All minimum/maximum specifications apply over the entire recommended operation range, unless otherwise noted. All typical specifications are at TA = 25°C, VDD1 = 5 V, VDD2 = 3.3 V, unless otherwise noted. Table 1.
PAGE 4
ADM2482E/ADM2487E Parameter TRANSFORMER DRIVER Oscillator Frequency Symbol Min Typ Max Unit Test Conditions fOSC 400 230 RON VSTART 600 430 1.5 2.5 kHz kHz Ω V kV/μs VDD1 = 5.0 V VDD1 = 3.3 V Switch-On Resistance Start-Up Voltage COMMON-MODE TRANSIENT IMMUNITY 1 500 330 0.5 2.2 1 25 VCM = 1 kV, transient magnitude = 800 V CM is the maximum common-mode voltage slew rate that can be sustained while maintaining specification-compliant operation.
PAGE 5
ADM2482E/ADM2487E PACKAGE CHARACTERISTICS Table 4.
PAGE 6
ADM2482E/ADM2487E VDE 0884-2 INSULATION CHARACTERISTICS This isolator is suitable for basic electrical isolation only within the safety limit data. Maintenance of the safety data must be ensured by means of protective circuits. An asterisk (*) on packages denotes DIN V VDE V 0884-10 approval. Table 7.
PAGE 7
ADM2482E/ADM2487E ABSOLUTE MAXIMUM RATINGS Each voltage is relative to its respective ground; TA = 25°C, unless otherwise noted. Table 8. Parameter VDD1 VDD2 Digital Input Voltages (DE, RE, TxD) Digital Output Voltages RxD D1, D2 Driver Output/Receiver Input Voltage Range Average Output Current per Pin ESD (Human Body Model) on A, B, Y, and Z pins Operating Temperature Range Storage Temperature Range Lead Temperature Soldering (10 sec) Vapor Phase (60 sec) Infrared (15 sec) Rating −0.5 V to +6 V −0.
PAGE 8
ADM2482E/ADM2487E D1 1 16 VDD2 D2 2 15 GND2 14 A 13 B 12 Z RE 6 11 Y DE 7 10 NC TxD 8 9 GND2 GND1 3 VDD1 4 RxD 5 ADM2482E/ ADM2487E TOP VIEW (Not to Scale) NC = NO CONNECT 07379-002 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS Figure 2. Pin Configuration Table 9. Pin Function Descriptions Pin No. 1 2 3 4 Mnemonic D1 D2 GND1 VDD1 5 RxD 6 RE 7 8 9 10 11 12 13 14 15 16 DE TxD GND2 NC Y Z B A GND2 VDD2 Description Transformer Driver Terminal 1. Transformer Driver Terminal 2.
PAGE 9
ADM2482E/ADM2487E TYPICAL PERFORMANCE CHARACTERISTICS 2.30 60 NO LOAD 54Ω LOAD 120Ω LOAD 50 SUPPLY CURRENT IDD1 (mA) 2.20 2.15 2.10 2.05 60 85 0 –40 60 85 NO LOAD 54Ω LOAD 120Ω LOAD 30 25 20 15 10 5 10 35 TEMPERATURE (°C) 60 85 tDPHL 400 300 200 100 0 –40 07379-030 –15 tDPLH 500 –20 0 20 40 60 80 TEMPERATURE (°C) Figure 4. ADM2487E IDD2 Supply Current vs. Temperature (See Figure 25) (Data Rate = 500 kbps, VDD1 = 5 V, VDD2 = 3.
PAGE 10
ADM2482E/ADM2487E 0.32 0 0.30 –20 OUTPUT VOLTAGE (V) –30 –40 –50 0.28 0.26 0.24 0.22 –60 0 1 2 3 4 5 OUTPUT VOLTAGE (V) 0.20 –40 07379-016 –70 –20 0 20 40 60 80 TEMPERATURE (°C) 07379-019 OUTPUT CURRENT (mA) –10 Figure 12. Receiver Output Low Voltage vs. Temperature (IDD2 = 4 mA) Figure 9. Output Current vs. Receiver Output High Voltage 60 D1 40 30 1 20 D2 10 0 1 2 3 4 5 OUTPUT VOLTAGE (V) CH1 2.0V Ω CH2 2.0V Ω M400ns 125MS/s 8.0ns/pt Figure 10.
PAGE 11
ADM2482E/ADM2487E T TxD 1 TxD Z, B 1 2 Z, B 2 Y, A Y, A RxD 4 RxD CH2 2.00V CH4 2.00V M 200ns T 47.80% A CH2 1.72V CH1 2.0V Ω CH2 2.0V Ω CH3 2.0V Ω CH4 2.0V Ω Figure 15. ADM2487E Driver/Receiver Propagation Delay, Low to High (RDIFF = 54 Ω, CL1 = CL2 = 100 pF) M 40.0ns 1.25GS/s IT 16.0ps/pt A CH2 1.68V 07379-037 CH1 2.00V CH3 2.00V 07379-035 4 Figure 17.
PAGE 12
ADM2482E/ADM2487E TEST CIRCUITS VOD2 RL 2 RL 2 VOC S1 Figure 22. Driver Enable/Disable 375Ω A 60Ω 375Ω V TEST Z Figure 20. Driver Voltage Measurement VOUT RE B CL Figure 23. Receiver Propagation Delay +1.5V TxD VCC S1 Y CL RL –1.5V RE CL RE IN Figure 21. Driver Propagation Delay Figure 24. Receiver Enable/Disable VDD2 VDD1 VDD2 GALVANIC ISOLATION DE TxD Y Z 120Ω A RxD B GND2 Figure 25. Supply Current Measurement Test Circuit Rev.
PAGE 13
ADM2482E/ADM2487E SWITCHING CHARACTERISTICS VDD1 VDD1 /2 VDD1 /2 VDD1 0V tDPLH tDPHL DE Z tZL tDSKEW = |tDPLH – tDPHL | 90% POINT VDIFF Y, Z VOL + 0.5V VOL tZH 90% POINT VDIFF = V(Y) – V(Z) tLZ 2.3V tHZ 2.3V VOH 10% POINT tDR 07379-010 10% POINT VOH – 0.5V Y, Z tDF 0V Figure 26. Driver Propagation Delay, Rise/Fall Timing 07379-012 Y –VO 0.5VDD1 0V 1/2VO VO +VO 0.5VDD1 Figure 28. Driver Enable/Disable Timing 0.7VDD1 RE 0.5VDD1 0.5VDD1 0.
PAGE 14
ADM2482E/ADM2487E CIRCUIT DESCRIPTION ELECTRICAL ISOLATION TRUTH TABLES In the ADM2482E/ADM2487E, electrical isolation is implemented on the logic side of the interface. Therefore, the part has two main sections: a digital isolation section and a transceiver section (see Figure 30).
PAGE 15
ADM2482E/ADM2487E MAGNETIC FIELD IMMUNITY The limitation on the magnetic field immunity of the iCoupler is set by the condition in which an induced voltage in the receiving coil of the transformer is large enough to either falsely set or reset the decoder. The following analysis defines the conditions under which this may occur. The 3 V operating condition of the ADM2482E/ADM2487E is examined because it represents the most susceptible mode of operation.
PAGE 16
ADM2482E/ADM2487E APPLICATIONS INFORMATION PRINTED CIRCUIT BOARD LAYOUT ISOLATED POWER SUPPLY CIRCUIT The isolated RS-485 transceiver of the ADM2482E/ADM2487E requires no external interface circuitry for the logic interfaces. Power supply bypassing is required at the input and output supply pins (see Figure 33). The ADM2482E/ADM2487E integrate a transformer driver that, when used with an external transformer and linear voltage regulator (LDO), generates an isolated 3.
PAGE 17
ADM2482E/ADM2487E line must be terminated at the receiving end in its characteristic impedance, and stub lengths off the main line must be kept as short as possible. For a half-duplex operation, this means that both ends of the line must be terminated, because either end can be the receiving end. TYPICAL APPLICATIONS Figure 35 and Figure 36 show typical applications of the ADM2482E/ADM2487E in half-duplex and full-duplex RS-485 network configurations.
PAGE 18
ADM2482E/ADM2487E OUTLINE DIMENSIONS 10.50 (0.4134) 10.10 (0.3976) 9 16 7.60 (0.2992) 7.40 (0.2913) 8 1.27 (0.0500) BSC 0.30 (0.0118) 0.10 (0.0039) COPLANARITY 0.10 0.51 (0.0201) 0.31 (0.0122) 10.65 (0.4193) 10.00 (0.3937) 0.75 (0.0295) 0.25 (0.0098) 2.65 (0.1043) 2.35 (0.0925) SEATING PLANE 45° 8° 0° 0.33 (0.0130) 0.20 (0.
PAGE 19
ADM2482E/ADM2487E NOTES Rev.